Heat a large pot over medium-high heat. Add oil and heat until shimmering.
Add onion, garlic, carrots, celerv and squash. Cook 3-4 minutes or until onions are translucent.
Add tomato paste and cook 3-4 minutes or until paste is dark red.
Add vegetable broth, scraping the bottom of the pan to release all the tomato paste mixture. Bring liquid to a simmer.
Add barley, beans, herbs, salt and pepper and bring to a boil.
Reduce heat to a simmer, cover with a lid and cook for nearly an hour until barley is tender, stirring occasionally. For quick barley, cook as directed on the package.
Stir in spinach and serve.